feat(dashboard): Bongbetic wordmark in header + monogram favicon

- Header now shows the Bongbetic icon + light/dark wordmark (linked to
  bongbetic.com) next to FENRIS — no more lonely "F" placeholder.
- Footer gets the little b_glyph monogram for that extra polish.
- Wires up real favicons (ico + 16/32) and apple-touch-icon + webmanifest
  so the tab and bookmarks actually look like Bongbetic.
- Vendors the missing brand bits: favicon set, apple icon, 192px icons,
  hi-res wordmark and contact sheet.

assets/bongbetic-brand/site.webmanifest

@@ -0,0 +1,11 @@
+{
+  "name": "Bongbetic Console",
+  "short_name": "Console",
+  "icons": [
+    { "src": "/icon-dark-192.png", "sizes": "192x192", "type": "image/png" },
+    { "src": "/icon-dark-512.png", "sizes": "512x512", "type": "image/png" }
+  ],
+  "theme_color": "#000000",
+  "background_color": "#000000",
+  "display": "standalone"
+}